As a method of obtaining biological information, there is a technology that can detect the biological information in real time in a non-contact manner using the microwave or a camera. Particularly, recently, pulse detection using the cameras is spreading by being mounted on a portable terminal in which miniaturization of a camera module is progressed including a smartphone.
As a technology of performing the pulse detection by imaging, there is a method of specifying a pulse signal from spectrum distribution of a time series signal (PTL 1).